for active duty military, federal workers and a slew of other programs. never before has raising the debt ceiling been so difficult. congress has done it 102 times since 1917, ten times in the last decade. this time, the treasury says there is no room for a last- minute deal. as negotiations drag on, credit rating agencies have threatened to downgrade america's credit. if they do, that will increase the cost to borrow money adding even more to the federal debt. whit johnson, cbs news, washington. >> mitchell: for more perspective on the debt talks and the politics behind them, we are joined in washington by our political analyst in washington, john dickerson. good evening. >> good evening. >> mitchell: give us an idea of the dynamics of a meeting like this. >> president obama is making a last pitch for that bigger deal, something close to $4 trillion in deficit reductions, arguing to republicans that if he's willing to take heat from democrats on the idea of trimming entitlements like social security and medicare, they should be open to the idea of raising revenue through doing something in the tax code. he'll say this is a unique moment.